I have 2 vCenter connected by linked mode. There's production site and DR site. Both version are 6.0U3. The vCenters are planned to upgrade to 6.5U2.
I read through the article saying the proper upgrade method is to upgrade the PSC on both sites first then only upgrade the vCenters. Which site PSC need to be upgraded first?
After the successful upgrade of all Platform Services Controller instances in the domain
Do all your PSC's first - if they are in the same SSO domain. Since they are replicating, its not ideal to have a mixed PSC nodes on 6.0---> sending info to 6.5 and back again
If you have separate PSC's then as per Upgrading the vCenter Server Appliance and Platform Services Controller Appliance
Important:
For topologies with external Platform Services Controller instances, you must upgrade the replicating Platform Services Controller instances in a sequence. After the successful upgrade of all Platform Services Controller instances in the domain, you can perform concurrent upgrades of multiple vCenter Server appliances that point to a common external Platform Services Controller instance.
As for which site - thats up to you. Personally I would start with DR
As always ensure you have valid backups before
So by the meaning of "upgrade the replicating Platform Services Controller instances in a sequence" is start in any site PSC after the first site completed only continue the other site PSC?
After the successful upgrade of all Platform Services Controller instances in the domain
Do all your PSC's first - if they are in the same SSO domain. Since they are replicating, its not ideal to have a mixed PSC nodes on 6.0---> sending info to 6.5 and back again